This is a Hidden Gift (only Koldun may learn this Gift)
"The Gift of Faerie is named for the legendary deceptive lords of illusion. Koldun with this gift are often tricky and in fact the gift enhances their ability to lie and otherwise deceive.
"Use of this gift allows the koldun to fool the senses, including magical ones. While the most famous ability is illusions that fool all senses, more commonly, the koldun using this gift uses a narrower scope. Invisibility can be performed easily, although adding senses past sight becomes harder. Stories state an invisible koldun casts a thin shadow; this is not entirely true, but the illusion is never perfect and some disturbance may be noticed by a sharp-eyed viewer. A subset of this trick is shield an area from magical scrying. This is much more reliable than trying to make a person invisible, but does not alert the koldun to such attempts.
"The legendary illusions of the Faerie Lords are not practiced by Koldun, but they can attempt something similar. A static illusion targeting one sense (sight usually) is easy, movement is harder and coherent illusions fooling multiple senses can be quite difficult.
"Despite legends and tales to the contrary, cold iron does not break illusions, nor does drawing blood, turning one's clothes inside out, etc. On the other hand, an illusion making someone believe that they are wounded cannot kill, at most it can stagger someone temporarily as they deal with the pain."